Exam 4 Ch 21 Flashcards
Types of plant hormones
Auxins Gibberellins Cytokinins Abscisic Acid Ethylene
Auxins Funtion
Soften the cell wall so plants can grow
Prevent leaf and fruit drop
Involved in phototropism and Gravitropism
Maintains apical dominance
Gibberellins Funtions
Promote stem elongation
Influence germination of seeds
Break seed and bud dormancy
Cytokinins Function
Promote Cell Division
Promote differentiation
Prevent Senescence
Abscisic Acid Funtion
Initiates and maintains seed and bud dormancy
Promotes formation of winter buds
Promotes closure of stomata
Ethylene Function
Promotes abscission (Leaf flower fruit Drop) Promotes Ripening of fruit
Potential Hormone applications in agriculture
Synthetic Auxins are sprayed on plants to induce development of fruit without pollination
Gibberellins are commonly used on grapes to increase size
How does photoperiodism work
the physiological reaction of organisms to the length of day or night
the developmental responses of plants to the relative lengths of light and dark periods which can control flowering in many plants
Flowering plants sex organs
Stamen
Carpel
What becomes the seed in a flowering plant
Ovule
What becomes the fruit in a flowering plant
Ovary
Development of the seed
Seed coat is derived from the ovule
Endosperm(1st result of double fertilization) sotres food for embryo
Cotyledones absorb endosperm
Embryo(2nd result of double fertilization)
Tissue specialization occurs in embryo
Process that leads to seeds
A pollen grain develops a pollen tube and sperm move down the tube to embryo sac
After sperm fertilizes an egg, the zygote becomes an embryo
Structure that houses the embryo becomes the seed
Possibilities of flower sexes
Bisexual
Unisexual
Types of Unisexual plants
Monecius
Diocious
